Industrial processes often leak fluids in liquid and gaseous state that are contaminants and pose a threat to the natural environment. These discharges may be the on-going byproduct of a process or they may be the result of an accident such as operator error, a fire or an explosion. Either way, it is imperative that these contaminants not be allowed to enter natural water flows or the atmosphere. Industrial facilities have a large number of access conduits to the natural environment such as floor drains and exhaust stacks and vents. These conduits are permitted to discharge fluids into the natural environment either in a non-contaminated state or at permissible contamination thresholds established by law. Beyond these thresholds, the contaminated discharges are not environmentally benign and are unlawful under environmental laws and regulations. Therefore, there is a need to maintain control over discharge of contaminated fluids into the natural environment by ensuring that fluid conduits can be closed before contaminated fluids can pass through them.
Industry relies upon a variety of apparatus and methods to control or prevent contaminated fluid discharges. Absorbents may be used to absorb contaminants spilled onto a surface. However, this is often “after-the-fact” and will not stop contaminants from entering a drain. Ventilation dampers may close upon a leak of contaminated fluid but the dampers may not seal the conduit entirely and may be too slow to adequately respond to a large release of contaminants. Closure valves can be inserted into fluid conduits downstream of drains to prevent the discharge of contaminated fluids. However, these valves may failure to close due to mechanical problems or close too slowly to prevent leakage. In many industrial facilities the valves can only be actuated by a human operator and this type of procedure has its own innate unreliabilities and deficiencies.
Therefore, there is an on-going requirement to automatically, swiftly and reliably close fluid conduits that have access to the natural environment before any contaminant can reach the natural environment.